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Dynamics of polar surfaces on ceria nanoparticles observed in situ with single-atom resolution

Möbus, G., Saghi, Z., Sayle, D.C., Bhatta, U.M., Stringfellow, A., Sayle, T.X.T. (2011) Dynamics of polar surfaces on ceria nanoparticles observed in situ with single-atom resolution. Advanced Functional Materials, 21 (11). pp. 1971-1976. ISSN 1616301X (ISSN). (doi:10.1002/adfm.201002135) (The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided)

The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided. (Contact us about this Publication)
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Abstract

Atomic hopping processes on ceria nanoparticle surfaces are observed by in situ phase contrast high-resolution electron microscopy with an aberration-corrected imaging lens. It is shown that single-atom resolution is possible, and single-atom dynamics for cerium are observable. Discrete changes in contrast and discrete positional changes of contrast maxima can be safely interpreted as visual fingerprints of atomic displacements. Both single-atom movements and spontaneous sequential relocations of entire atomic rows are observed. Exclusive occurence of the effect on {100} type facets indicates polar dipole field mediated atomic rearrangements, while {111} facets are found to be stable. Molecular modelling confirms that the relocations follow genuine pathways involving partially occupied oxygen-terminated surfaces, by means of temperature induced fluctuations. A series of images tracks the detailed atomic motions over a time of 120 s and quantifies the ratio of reversible atom hopping versus atom ablation. The observation of single-atom movements at the surface of a solid is one of the ultimate goals of microscopy. Using atomic-resolution aberration corrected transmission electron microscopy and exploiting the inherent instability of CeO2 (100) nanoparticle surface facets, a series of images that demonstrate a hopping sequence of Ce atoms could be recorded in 2 s intervals. Important insights into the surface activity of ceria are gained, which are of high relevance for catalysis and other surface-activity related applications. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Item Type: Article
DOI/Identification number: 10.1002/adfm.201002135
Additional information: Unmapped bibliographic data: LA - English [Field not mapped to EPrints] J2 - Adv. Funct. Mater. [Field not mapped to EPrints] AD - Department of Materials Science and Engineering, University of Sheffield, Sheffield, S1 3JD, United Kingdom [Field not mapped to EPrints] AD - Department of Applied Science, Security and Resilience, Cranfield University, Shrivenham, Swindon, SN6 8LA, United Kingdom [Field not mapped to EPrints] AD - Department of Materials Science and Metallurgy, University of Cambridge, Cambridge, CB2 3QZ, United Kingdom [Field not mapped to EPrints] DB - Scopus [Field not mapped to EPrints]
Uncontrolled keywords: aberration-corrected TEM, cerium oxide, dynamic TEM, nanoparticles, single-atom imaging, surface structure, Atomic displacement, Atomic hopping, Atomic motion, Atomic rearrangements, Atomic rows, Atomic-resolution, Ceria nanoparticles, Cerium oxides, Dipole fields, Hopping sequences, Imaging lens, In-situ, Inherent instability, Molecular modelling, Nanoparticle surface, Oxygen-terminated surfaces, Phase contrasts, Polar surfaces, single-atom imaging, Surface activities, TEM, Temperature-induced, Cerium, Cerium compounds, High resolution electron microscopy, Molecular oxygen, Nanoparticles, Surface structure, Transmission electron microscopy, Atoms
Subjects: Q Science
Divisions: Faculties > Sciences > School of Physical Sciences > Functional Materials Group
Depositing User: Dean Sayle
Date Deposited: 27 Jan 2015 16:43 UTC
Last Modified: 29 May 2019 14:06 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/46780 (The current URI for this page, for reference purposes)
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